1. Field of the Invention
The present disclosure is related to cutting implements. More particularly, the present disclosure is related to knives, and more specifically to utility knives configured for enhanced safety during their use.
2. Description of Related Art
Knives are well known in the art and are currently available is various forms. Such forms include fixed blade knives, folding knives, utility knives, and the like.
Fixed bladed or straight knives typically have a protective sheath for storage for covering the exposed blade. Such sheaths are constructed using thick leather sheets to ensure a safe covering of the blade during transport and storage. If the sheath is lost or damaged, the knife may produce an inadvertent cutting hazard. These types of knives are also bulky due to the combined length of the handle and blade.
Folding knives are also well known in the art. These knives typically have a handle and a blade pivotably associated with the handle. When the blade is not in use, the blade can be folded where the cutting edge is contained inside an opening of the handle. This allows safer and less bulky storage of the knife when not in use or during transport. However, there still exists a hazard with such knives. During use, the user is required to grasp the handle which places the hand in the path of the handle opening. During use, it has been observed that the blade can close and cause an inadvertent cut when moving towards the opening of the handle. It has also been observed that the opening and closing of such folding knives typically requires a two-handed operation. When attempted to open or close such folding knives using a single hand, difficulty is encountered which can increase the chance of injury.
In order to mitigate this effect, folding knives have been configured to maintain the blade in the open position during use. This has been known to reduce inadvertent closing of the blade during use. However, this type of mechanism employed typically consists of a spring loaded arm configured to mate with a first flat on a cylindrical surface of the rotating blade. The flat is placed at a predetermined location allowing the blade to remain in the desired open (cutting) position. The spring force of the arm maintains the blade in the open position. During use, it has been observed that these types of knives can cause injury. For example, if the spring force holding the blade can be overcome during use, the blade can close on the user's hand during handling. In addition, these folding knives are configured to also keep the blade in the closed position inside the handle. The same spring force is also applied to a second flat opposite the first flat. Unfortunately, the transition to the second flat from the cylindrical surface typically causes the blade to accelerate into the closed position from the spring force. This acceleration has been known to cause inadvertent cuts during the closing or use of such folding knives. As detailed above, these types of folding knives also require a two-handed operation.
Some improvements have been employed to ensure the blade remains locked in the open (cutting) position during use. These improvements have been known to eliminate inadvertent closing of the blade during use. This type of mechanism is similar to the above and typically consists of a spring loaded arm with a tab on a first end and a user actuator on a second end. The tab is configured to fit within a locking recess contained on a cylindrical surface on the rotating blade. The locking recess is placed at a predetermined location allowing the blade to remain locked in the desired open position. As described above, these locking knives are also configured to keep the blade in the closed position inside the handle. The spring loaded arm is also applied to a flat contained on a portion of the cylindrical surface opposite the blade locking recess. During closure of the blade, the user typically depresses the actuator to release the blade and begins to fold the blade in the closed position. Before closure, the user typical releases the actuator and the tab on the spring loaded arm rests on a cylindrical surface. Unfortunately, the transition to the flat typically causes the blade to accelerate into the closed position from the spring force. This acceleration has been known to cause inadvertent cuts during the closing of such folding knives. As detailed above, these types of folding knives still require the aforementioned two-handed operation.
Utility knives are well known. These types of knives typically allow the use of disposable blades to avoid the need of blade sharpening. Many forms are available such as a retractable version. The blade is disposed, for example within its housing, and can be selectively extended and retracted by engaging an external member. The external member actuates a carriage which houses the blade and allows the user the ability to retract the blade.
Folding utility knives have been increasing in popularity. These utility knives typically consist of substantially similar mechanisms as the aforementioned folding knives with the added feature of selectively retaining and removing disposable blades. Unfortunately, since these mechanisms are substantially similar as detailed above, they too suffer from the same concerns as the above mentioned folding knives.
The knives as described above also lack operational resistance when left unattended. Such knives can cause injury to a child if encountered.
Therefore, there is a need for knives that overcome, alleviate, and/or mitigate one or more of the aforementioned and other deleterious effects of prior art knives.